I’m looking to get a smidgin more oomph out of my board.
Can get a review of my numbers?
First off the board:
Flipsky 190kv 6374s
ESC is focbox unity 3m taped to the plastic enclosure (no heatsink)
Battery is 12s4p p42a.
My numbers:
Motor Current Max: 80A
Absolute Max Current: 400A
Battery Current Max: 80A
MOSFET Temp Cutoff Start: 85C
MOSFET Temp Cutoff End: 100C
Motor Temp Cutoff Start: 85C
Motor Temp Cutoff End: 100C
Maximum Duty Cycle: 95%
Duty Cycle Current Limit Start: 85%
I’d put this back to a sane value like 250A. Set fault time to 150ms or so. That setting is there to protect the mosfets from exploding in case of a current spike. If you get faults then you can tweak stuff like checking connectors, motor windings, motor values, etc.
I set this to 93% for a bit more top speed.
But the biggest bang for your buck is going to be gearing/wheel size. A loaded top speed somewhere around 40 mph on the esk8 calculator has a ton of torque at your settings.
Yeah. This board is DKP so I can’t take it to top speed anyway without it getting all squirrelly.
Do you mean “Fault Stop Time”? (It’s currently set to 500ms)
I’ll change this one if I wind up hitting top speed but unlikely on this board.
Yeah I’ve got 175mm / 7-inch tires on this board right now which is why I’m feeling the lack of torque a bit.
They are too floaty too.
Probably going back to the 6-inchers once I run these down so I’ll get a bit of torque back there.
Gearing is 15/66. I think changing the gearing is too involved.
Yes, 500ms is downright dangerous. In fact, I would change it to like 85ms or 100ms tops on that setup. Enough to feel and be be effective, but not quite enough to knock you off balance really badly.
I’ve got a 4wd build that I’m working on and it will use two MakerX DV6 escs. I’m trying to figure out how to wire this, since in traditional loop key wiring, all of the current goes through it
I’ve been using some of my worn metal cutting disks to cut plastic. It will kind of melt a bit of the plastic but the melty bits can be pulled off. I also used some sanding drums to even out the cut since I can’t cut at perpendicular to the surface apparently.
Here is the disk I am using as well as trying to show what I mean by melty bits.
On the right side are pieces I just gently pulled on and they are already coming off. Also added the large piece to show how clean of a line you can get even when not being super careful.
I’ll post this here since it is pretty nooby and will probably be seen more. I want a more accurate battery gauge for my Zeus pro and was thinking about one of these little cheapo LCD gauges:
It’s listed as handling up to 15S li-ion battery config. I can make up a mount for it but for wiring is it as easy as using some posi-taps on the battery leads (after the switch preferably)? Not looking to create a fire hazard so whatever’s safest.
I’m looking at brushless scooter hub motors. Do you have any knowledge about those? Most of them are 36 to 48 volt, 350 to 500 watt jobbies. I’ve seen a few that list the torque. I think one said 8 nm. Can you advise me on what wattage range I should be looking at? I weigh 190 and the rig will probably be, don’t know, 30, 40 pounds. Torque range as well?
I have some adjacent knowledge (Ebike motors are similar, and I know a good bit about those.)
First, those nominal voltage ratings can and should be ignored. They don’t tell you anything.
The power ratings are not much better, at best being “suggestions” about the maximum continuous power, and can be far exceeded (500% or more easily) for short periods of time with no ill effect as long as you keep an eye on the stator temp.
The best number you can find, and the one that will give you the most information, is KV, which is RPM/volt. KV is inversely proportional to KT, which is torque per amp. Lower KV = higher KT.
KT = 9.547 ÷ KV gives the resulting KT value in newton-meters, so a scooter motor with a KV of 10, would mean a KT of 0.954 N*M/A. The max torque each motor can achieve is limited by how much current it can handle without overheating or going into magnetic saturation.
I think you would probably be happier with that than most hub motors, due to the better gear ratio, reduced weight, and much improved cooling.
